The present invention relates to processing rolled dough products. More particularly, the present invention relates to cooling filling in a rolled dough product prior to rolling the dough.
Dough processors for processing rolled dough products are known. Conventional rolled dough processors provide a sheet of dough on a conveyor. The conveyor moves the dough through a series of knives or cutters which slit and score the dough. The dough is then advanced beyond the cutters, and filling is applied to the top of the dough as it advances.
Once the filling is applied to the dough, the individual dough pads which were slit and scored by the cutters are rolled up to form the rolled dough product. After being rolled, the filling which previously resided on the top of the dough sheet, is rolled within the dough product as the desired filling. Once the product is rolled, it is packaged in cans or other suitable packages.
Certain problems commonly arise in rolled dough processors. The filling which is typically applied to the dough is fat-based filling giving it a changing viscosity profile over a temperature range. It has traditionally been applied to the dough by spraying. The filling is sprayed through a pressurized atomizing or dispersion nozzle. In order for the filling to be sprayable, it must be heated to become less viscous than it is at typical room temperatures. However, the less viscous filling sprayed on the surface of the dough presents problems during the rolling process.
The rolling process is typically initiated by raising the leading edge of the individual pads of dough cut by the cutters. The leading edge of each pad is raised and then rolled back over the remainder of the dough pad. It is intended that the leading edge of the pad "grab" the remainder of the dough pad such that, as rolling force is exerted on the pad, the dough pad rolls up on itself in a tight cylindrical roll.
However, because the filling is heated before it is sprayed, the filling looses viscosity and becomes "slippery". Thus, as the leading edge of the dough pad is rolled back upon itself, it engages the slippery filling and, rather than grabbing and rolling, it simply slips along the slippery surface and ends up having only a single fold, being very loosely rolled, or being rolled but having an elliptical cross-section. All of these are undesirable both from an aesthetic stand point (which is a consumer perception issue), and because such non-cylindrical dough products cause difficulty during the packaging operation.
In order to overcome this problem, a number of modifications to the process have been attempted. The first modification was simply to decrease the amount of filling applied to the dough. While this was somewhat successful in making the dough products more rollable, it is desirable from a taste standpoint to fill the dough products with reasonably high levels of filling. Thus, decreasing the amount of filling applied to the dough is undesirable.
Another attempted solution to the present problem was to change the type of fat used in the filling. However, this proposed solution is undesirable because there are only a limited number of fats which can be used, due to the characteristics sought in the fat. For example, the filling must be solid at refrigerated temperatures so it will not flow in packaging. This is also required to maintain some acceptable modicum of shelf life. Thus, switching fats is generally considered undesirable. In this regard, since water-based fillings have a non-changing viscosity profile over temperature, they are unacceptable as well.
Another attempt to overcome the problems encountered in processing rolled dough products was to use cooler (and hence more viscous) filling. Such viscous filling is not easily pumpable or sprayable. Thus, the filling was applied to the dough products in strips using an extrusion process. However, this resulted in other problems.
In the extrusion process, the filling was pumped to an extrusion manifold and the filling was extruded onto the dough. However, the extrusion process was not easily controllable and suffered from large performance variations. One major problem associated with the extrusion process was that it was very difficult to uniformly disperse the filling across the extrusion manifold. This resulted in wide variation in filling levels across the dough sheet. Another major problem encountered was that the cooler filling tended to solidify in the extrusion equipment rendering the equipment essentially inoperable without frequent cleaning. These problems greatly increased manufacturing shrink (or waste) when increased filling levels were applied to the dough.